- tvector3f[0] = ((tc1[0] - tc0[0]) * (v2[0] - v0[0]) - (tc2[0] - tc0[0]) * (v1[0] - v0[0]));
- tvector3f[1] = ((tc1[0] - tc0[0]) * (v2[1] - v0[1]) - (tc2[0] - tc0[0]) * (v1[1] - v0[1]));
- tvector3f[2] = ((tc1[0] - tc0[0]) * (v2[2] - v0[2]) - (tc2[0] - tc0[0]) * (v1[2] - v0[2]));
- f = -DotProduct(tvector3f, normal3f);
- VectorMA(tvector3f, f, normal3f, tvector3f);
- VectorNormalize(tvector3f);
- // note: can't be a CrossProduct as that sometimes flips the texture
- svector3f[0] = ((tc1[1] - tc0[1]) * (v2[0] - v0[0]) - (tc2[1] - tc0[1]) * (v1[0] - v0[0]));
- svector3f[1] = ((tc1[1] - tc0[1]) * (v2[1] - v0[1]) - (tc2[1] - tc0[1]) * (v1[1] - v0[1]));
- svector3f[2] = ((tc1[1] - tc0[1]) * (v2[2] - v0[2]) - (tc2[1] - tc0[1]) * (v1[2] - v0[2]));
- f = -DotProduct(svector3f, normal3f);
- VectorMA(svector3f, f, normal3f, svector3f);
+ // 12 multiply, 10 subtract
+ tc10[1] = tc1[1] - tc0[1];
+ tc20[1] = tc2[1] - tc0[1];
+ svector3f[0] = tc10[1] * v20[0] - tc20[1] * v10[0];
+ svector3f[1] = tc10[1] * v20[1] - tc20[1] * v10[1];
+ svector3f[2] = tc10[1] * v20[2] - tc20[1] * v10[2];
+ tc10[0] = tc1[0] - tc0[0];
+ tc20[0] = tc2[0] - tc0[0];
+ tvector3f[0] = tc10[0] * v20[0] - tc20[0] * v10[0];
+ tvector3f[1] = tc10[0] * v20[1] - tc20[0] * v10[1];
+ tvector3f[2] = tc10[0] * v20[2] - tc20[0] * v10[2];
+ // 12 multiply, 4 add, 6 subtract
+ f = DotProduct(svector3f, normal3f);
+ svector3f[0] -= f * normal3f[0];
+ svector3f[1] -= f * normal3f[1];
+ svector3f[2] -= f * normal3f[2];
+ f = DotProduct(tvector3f, normal3f);
+ tvector3f[0] -= f * normal3f[0];
+ tvector3f[1] -= f * normal3f[1];
+ tvector3f[2] -= f * normal3f[2];
+ // 2 sqrt, 2 divide, 12 multiply, 4 add, 2 compare